WEEK 3

FOCAL LENGTH

Focal length alters distances and heights.

Can change a persons face, exaggerate speed, or cause motion to appear suspended.

Different use of Focal Length makes objects look small, big, far away, or close.

Focal Length makes backgrounds appear sharply focus, slight soft, or completely out of focus.

Focal Lengths are achieved with the physical lenses use in a scene (Wide Lens, Normal Lens, and Telephoto Lens), and in "FILM" different f-stop.
Remember we don't use f-stop in digital video.

SHORT FOCAL LENGTH (WIDE ANGLE LENSES)

• Exaggerate distances from the camera. Often use in establishing shots, and panoramic shots
• Have great depth of field (much of background and foreground focus)
• Usually we need to have some action and/or design elements, to give the audience some cue where to focus their attention
• Camera movements are easier using these lenses
• Exaggerate perspective (parallel lines converge faster than with a naked eye)
• Near objects seems larger, and far objects seems smaller
• Good for high-speed sequences (objects increase size as they approach to the camera, car-mounted cameras)

NORMAL FOCAL LENGTH

Similar as we see perspective with our eyes

35mm film and photography: normal lens of 50mm

16mm film and video: normal lens of 25mm

Some video cameras use a normal lens that is shorter that the above

LONG FOCAL LENGTH (TELEPHOTO)

• Magnify a small portion of the scene
• Background progressively out of focus as focal length increase (close-up of a persons face, using these lenses, will show some features out of focus, while others in focus)
• RACK-FOCUSINGis the effect create by these lenses (subject in focus with background out of focus, or vice versa)
• Perspective is opposite to SHORT FOCAL LENGTH (parallel lines appear to converge farther away)
• Objects approaching or moving away from the camera change sizes much more slowly
• Compress space (bring backgrounds closer to the subjects)
• Camera movements are not easy using these lenses

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